/Engine/Source/Runtime/Engine/Classes/Components/PrimitiveComponent.h
Try and retrieve the material applied to a particular collision face of mesh. Used with face index returned from collision trace.
Material applied to section that the hit face belongs to
virtual [UMaterialInterface](API\Runtime\Engine\Materials\UMaterialInterface) * GetMaterialFromCollisionFaceIndex ( int32 FaceIndex, int32 & SectionIndex ) const